1. Technical Field
The present invention relates to a hose clamp.
2. Background Related Art
Hose clamps have conventionally been used for connection between piping and a hose. One type of such hose clamps is disclosed by Japanese Patent Application Publication No. JP-A-H08-93980. The disclosed hose clamp includes a body bent into an annular shape and having two ends formed with grip pieces which are raised from the ends and gripped by a tool, respectively. When gripped to come closer to each other, both grip pieces are elastically deformed radially relative to each other so that a lock portion provided on one grip piece runs onto a receiving portion which is provided on the other grip piece so as to protrude radially outward. After the lock portion has run onto the receiving portion, the grip pieces are returned with deformation, whereby the locking of the lock portion to the receiving portion is completed. Thus, the hose clamp is retained in an opened-diameter state and fitted with an outer circumference of a hose in the opened-diameter state prior to connection.
A bar-like releasing jig is used when a hose is to be clamped. A middle part of the releasing jig is applied to an upper end of the grip piece provided with the receiving portion, thereby serving as a fulcrum of leverage. A distal end of the releasing jig is then applied to a root of the other grip piece, thereby serving as an operating point of leverage. A releasing operation is carried out with the pivot point and the operating point.
As a result, when the body is elastically deformed in reverse order of the above-described elastic deformation in the locking operation to thereby be released from the locked state, the hose clamp is displaced at once by the elastic, restoring force of the body into a closed-diameter state.
Since leverage is used for the release of the hose clamp from the opened-diameter state in the above-described conventional art, the lengths of the respective grip pieces are set to different values for the purpose of smooth operation. More specifically, the grip piece serving as a fulcrum of the leverage (the side provided with the receiving portion) is rendered shorter.
Accordingly, when the grip pieces are gripped by a tool such as pliers for the purpose of transition from the closed-diameter state to the opened-diameter state, the tool assumes an inclined state to the shorter grip piece side, with the result that the shorter grip piece tends to be displaced so as to be lifted. When this occurs, a trajectory at the receiving portion side upwardly deviates from a normal trajectory during the locking operation, whereupon the lock portion cannot be locked to the receiving portion smoothly. This poses a failure.
The present invention was made in view of the foregoing circumstances and an object thereof is to provide a hose clamp which can smoothly be caused to transit from the closed-diameter state to the opened diameter state.